This invention relates to a method and apparatus for leveling a die on a die-forming machine, such as a stretch-wrapping machine. More specifically, the invention relates to a method and apparatus for automatically leveling a die supported on two die posts. Such machines are used to place bends in a metal member such as an extrusion, I-beam or the like. The machine functions by bending the member around a die to form it into the proper shape.
In one type of machine, the die is moved against the member while the ends of the member are clamped ;in jaws. In another type of machine, the die is held stationary and the jaws are mounted on arms which stretch the ends of the member around the die. An another type of machine, both the die and the jaws move. In either case, it is important to carefully adjust the die so that the member is urged against the die in exactly the correct orientation.
In many prior art die-forming machines, the die is mounted on one or more die posts. The die posts are adjustable with a pair of jack screws. A level is placed on top of the die and the jack screws are adjusted until the level indicates that the die is positioned correctly. This trial-and-error process is time-consuming because not only must the die be level, but it must be at exactly the correct vertical position, as well, in order to mate properly with the member being formed.
In this application the term "level" is used in the sense of correct orientation relative to the horizontal dimension, as distinguished from the vertical dimension. The method and apparatus according to the invention achieve both correct horizontal and vertical orientation simultaneously and automatically. Most often, the correct horizontal dimension will be one which is precisely 90 degrees from the vertical. However, other predetermined orientations can also be obtained according to the principles of this invention.